title: Elements of the polycomb repressor SU(Z)12 needed for histone H3-K27 methylation, the interface with E(Z), and in vivo function.
abstract: Polycomb repressive complex 2 (PRC2) is an essential chromatin-modifying enzyme that implements gene silencing. PRC2 methylates histone H3 on lysine-27 and is conserved from plants to flies to humans. In Drosophila melanogaster, PRC2 contains four core subunits: E(Z), SU(Z)12, ESC, and NURF55. E(Z) bears a SET domain that houses the enzyme active site. However, PRC2 activity depends upon critical inputs from SU(Z)12 and ESC. The stimulatory mechanisms are not understood. We present here functional dissection of the SU(Z)12 subunit. SU(Z)12 contains two highly conserved domains: an ∼140-amino-acid VEFS domain and a Cys2-His2 zinc finger (ZnF). Analysis of recombinant PRC2 bearing VEFS domain alterations, including some modeled after leukemia mutations, identifies distinct elements needed for SU(Z)12 assembly with E(Z) and stimulation of histone methyltransferase. The results define an extensive VEFS subdomain that organizes the SU(Z)12-E(Z) interface. Although the SU(Z)12 ZnF is not needed for methyltransferase in vitro, genetic rescue assays show that the ZnF is required in vivo. Chromatin immunoprecipitations reveal that this ZnF facilitates PRC2 binding to a genomic target. This study defines functionally critical SU(Z)12 elements, including key determinants of SU(Z)12-E(Z) communication. Together with recent findings, this illuminates PRC2 modulation by conserved inputs from its noncatalytic subunits.
authors.affiliation: Department of Genetics, Cell Biology, and Development, University of Minnesota, and Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Aswathy N
authors.initials: AN
authors.lastname: Rai
authors.forename: Marcus L
authors.initials: ML
authors.lastname: Vargas
authors.forename: Liangjun
authors.initials: L
authors.lastname: Wang
authors.forename: Erica F
authors.initials: EF
authors.lastname: Andersen
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Miller
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Simon
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D002843:Chromatin / Q000378:metabolism; D017124:Conserved Sequence; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000378:metabolism*; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D008745:Methylation; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism; D063151:Polycomb Repressive Complex 2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D011499:Protein Processing, Post-Translational; D017384:Sequence Deletion; D061987:Sf9 Cells; D018411:Spodoptera; D016335:Zinc Fingers
chemical_list: D002843:Chromatin; D029721:Drosophila Proteins; D006657:Histones; D009687:Nuclear Proteins; C543390:Su(z)12 protein, Drosophila; C083329:E(z) protein, Drosophila; D011495:Histone-Lysine N-Methyltransferase; C524066:PRC2 protein, Drosophila; D063151:Polycomb Repressive Complex 2